Partial molar volumes phi(0)(V) and viscosity B-coefficients of N,N'-ethylene-bis(salicylideneiminato)cobalt(II), abbreviated as Co(salen), in different mass fractions (0 to 0.40) of 1,4-dioxane + methanol mixtures were determined from solution density and viscosity measurements at (298.15, 303.15, 308.15, and 313.15) K under ambient pressure. Apparent molar volumes phi(V) and density data at the experimental temperatures were used to calculate the apparent molar expansibilities phi(E) of Co(salen) solutions; the partial molar expansibilities phi(0)(E) were then determined from the relation: phi(E) = phi(0)(E) + S(E)(m)(1/2). The temperature dependence of phi(0)(E) values yielded (partial derivative phi(0)(E)/partial derivative T)(Pj) the signs of the (partial derivative phi(0)(E)/partial derivative T)(P) values were discussed to reveal the structure promoting ability of Co(salen) in the experimental solvent/solvent mixtures. The activation parameters of viscous flow for the ternary solutions were also derived and discussed in terms of transition state theory. Various results indicated that the ternary system under investigation is characterized by structural changes and strong solute-solvent interactions.